title: Presence of Fe3+ and Zn2+ promoted biotransformation of Cd-citrate complex and removal of metals from solutions.
abstract: The promotion to Cd-citrate complex biotransformation via addition of Fe(3+) and Zn(2+) was investigated. Single Fe(III)- or Zn-citrate complex was completely degraded by Pseudomonas sp. MBR, Cd-citrate complex was not. In the Cd-citrate media with molar ratio of 1:2 and 1:3, pH increase obtained from the metabolism of excess citrate slightly promoted the biotransformation of Cd-citrate complex, Cd remained in solutions. The presence of Fe(3+) and Zn(2+) resulted in complete biotransformation of Cd-citrate complex in the 1:1:2 Fe:Cd:citrate and Zn:Cd:citrate and 1:1:1:3 Fe:Zn:Cd:citrate media. Alkaline pH obtained from biotransformation of metal-citrate complexes caused almost complete removal of metals (>98%) through precipitation and co-precipitation. Pseudomonas sp. MBR potentially could be used to treat wastewater containing mixed citrate complexes of Fe(III), Zn and Cd.
authors.affiliation: Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, China; Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu 610041, China; Key Laboratory of Environmental and Applied Microbiology, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, China. Electronic address: jwqian209@outlook.com.
authors.forename: Jun-Wei
authors.initials: JW
authors.lastname: Qian
authors.forename: Yong
authors.initials: Y
authors.lastname: Tao
authors.forename: Wen-Jie
authors.initials: WJ
authors.lastname: Zhang
authors.forename: Xiao-Hong
authors.initials: XH
authors.lastname: He
authors.forename: Ping
authors.initials: P
authors.lastname: Gao
authors.forename: Da-Ping
authors.initials: DP
authors.lastname: Li
mesh_terms: D001673:Biodegradation, Environmental; D001711:Biotransformation; D002104:Cadmium / Q000737:chemistry*; D019343:Citric Acid / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007501:Iron / Q000737:chemistry*; D007700:Kinetics; D008024:Ligands; D008670:Metals / Q000032:analysis*; D019216:Metals, Heavy / Q000737:chemistry; D011549:Pseudomonas / Q000378:metabolism*; D012995:Solubility; D012996:Solutions; D062065:Wastewater; D014874:Water Pollutants, Chemical / Q000032:analysis*; D018508:Water Purification / Q000379:methods; D015032:Zinc / Q000737:chemistry*
chemical_list: D002104:Cadmium; D019343:Citric Acid; D007501:Iron; D008024:Ligands; D008670:Metals; D019216:Metals, Heavy; D012996:Solutions; D062065:Wastewater; D014874:Water Pollutants, Chemical; D015032:Zinc
keywords: Bioremoval; Biotransformation; Heavy metal; Metal–citrate complexes; Pseudomonas sp. MBR